Sure, I can help you with that!

To change the font color and background color of a cell based on the value of a checkbox, you can use a simple VBA code. Here are the steps:

1. Right-click on the checkbox and select "Format Control".
2. In the "Control" tab, enter a cell link where the value of the checkbox will be stored. For example, you can enter "D3".
3. Close the "Format Control" dialog box.
4. Press "Alt + F11" to open the VBA editor.
5. In the editor, double-click on the sheet where the checkbox is located.
6. Paste the following code:
   
   
   Formula:

   Private Sub CheckBox1_Click()
    If Range("D3").Value = True Then
        [b]Range("A3:C3").Interior.Color = RGB(255, 255, 0)[/b] 'change background color to yellow
        [b]Range("A3:C3").Font.Color = RGB(255, 255, 0)[/b] 'change font color to yellow
        [b]Range("A3:C3").Borders.LineStyle = xlNone[/b] 'remove border lines
    Else
        [b]Range("A3:C3").Interior.Color = RGB(255, 255, 255)[/b] 'change background color to white
        [b]Range("A3:C3").Font.Color = RGB(0, 0, 0)[/b] 'change font color to black
        [b]Range("A3:C3").Borders.LineStyle = xlContinuous[/b] 'add border lines
    End If
End Sub 

7. Save the workbook and close the VBA editor.

Now, when you click on the checkbox, the font color and background color of cell A3, B3, C3 will change to yellow, and the border lines will be removed. When you uncheck the checkbox, the font color and background color will change back to black and white respectively, and the border lines will be added back.